Surveying instrument.



F. S. CLARK SURVEYING INSTRUMENT.

APPLICATION FILED MAR. 15. 1917.

Patented Sept. 4, 1917.

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F s. CLARK.- SURVEYING INSTRUMENT.

APPLICATION FILED MAR l5. l9]?- Patented Sept. 4, 191?.

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ATTORNEY FRANKLIN CLARK, OF DALLAS, TEXAS.

SURVEYING INsmUMEN'r.

Specification of Letters Patent.

Patented Sept. 4t, 1911 W.

Application filed March 15, 1917. Serial No. 155,000.

To all whom it may concern:

Be it known that I, FRANKLIN S. CLARK, a citizen of the United States, residing at Dallas, in the county of Dallas and State of Texas, have invented certain new and useful Improvements in Surveying Instruments, of which the following is a specification.

This invention has particular relation to that class of surveying and engineering i11- struments, known as levels and commonly referred to as Y levels. 1

Considerable experimenting has been done along the line of pivotally mounting the telescopes of levels. A serious objection to all such levels is that the telescopes of the same are not balanced and this is due to the relative location of the pivot point. Some have pivot points on each side of the telescope, while others have their pivots on each side of the supporting bar, frequently called level bar. The telescopes vary in length from twelve to twenty inches and the load sustained by the pivots is either all below or all above the axis of the pivots, which makes the telescope dificult to adjust accurately.

Furthermore it is quite difficult to rigidly fasten the telescope in its adjusted positions, especially where a long instrument isused. If the fastening isattempted by means d1sposed laterally of the telescope, there is a torsional axial strain to be overcome and I have found that the best results cannot be obtained by a lateral fastening.

My invention has for its essential feature the pivotal mounting and fastening of a level telescope in an efiicient manner whereby the telescope is substantially balanced; this being accomplished by the proper location of the pivotal axis together with a rigid fastening in its adjusted positions by means of elements located substantially central with relation to the longitudinal axis of the telescope.

In carrying out the invention the trans verse pivotal axis of the telescope 1s established relatively between the telescope and the supporting bar, with the result that the weight will be more equally distributed above and below the pivot point and the telescope substantially balanced. In order that the telescope and the supporting bar may be brought closer together the usual spirit level is removed from 'therebetween and otherwise mounted on the telescope.

While the supporting bar and telescope might be fastened in various manners I have found a very satisfactory arrangement to include a segment rigidly attached to the supporting bar and depending into a clamp mounted on the limb plate. The clamp fas tens the segment so that the telescope and bar are immovable. By adjusting the clamp relatively tangential of the segment the telescope may be swung in a vertical plane as desired. The segment may be graduated like a vertical arc and a Vernier provided. The fastening 0f the telescope is carried out on a line in substantially the same vertical plane as the longitudinal axis of the tele scope so that all torsional strain is eliminated.

The invention will be more readily understood from a perusal of the following specification and by reference to the accompanying drawings, wherein an example of the invention is shown and in which Figure 1 is a side elevation of an engineers level constructed in accordance with my invention,

Fig. 2 is a cross-sectional detail on the line 2-2 of Fig. 3,

Fig. 3 is a detail in elevation of the Vernier and its support,

Fig. iis a longitudinal sectional detail of the clamp and tangent fastening and adjusting device,

Fig. 5 is a plan view, the supporting bar, its shaft and the telescope being omitted, and

Fig. 6 is a transverse vertical sectional view taken on the line 66 of Fig. 1.

In the drawings the numeral 1 designates the usual leveling head on which is supported a limb or other supporting plate 2, ac-

cording to the desires of the builder. A pair I of spaced standards 3 are mounted on the plate as shown in the drawings. These standards have bearing boxes 4 at their upper ends receiving the reduced ends of a transverse shaft 5. At the central portion of the shaft a hanger 6 is rigidly fastened thereon and at right angles thereto. This hanger suspends an inverted channel bar 7, referred to herein as the supporting bar. This bar extends equally 011 each side of the shaft and at right angles thereto. The supporting bar is thus suspended between the standards 3 and is capable of oscillation in a vertical arc of approximately 70 degrees.

yoke member 10 said members being sub stantially Y-shaped and each being commonly known as a in the usual manner, leveling nuts 12 being mounted onathe members 10. As the invention relates to the pivotal mounting of the bar 7 and the telescope togetherwvithmeans for fastening the same in the positions to which'they are oscillated, no attempt will be made to describe the details of the other parts .ofrthe instrument which may be of any approyed type and form.-

CO-]11QlClO11l) with the vertical plane in which the longitudinal. axes of both the tele I,

scope and the bar 7, lie is a depending yer-- t1cal segment 14:. This segmentphas its upper ends securedqin the channet of the-bar, and is additionally supported by divergent braccs 15 also secured in the channel. These be castintegral iwith the bar by parts may means oft-webs 16, or they may be otherwise suitably fastened tothe bar in a rigid man- 7 nerzUIt-will be seen that the longitudinaL axisof theshaft 5 passesbetwecnthe tele-a scope and the supporting bar and thus the weight 1s distributed above and below. -tlie pivotal axis of-said p.arts,,whereby a more,

perfect balance s had and the oscillationof the; telescope is ;more readily carried out... By suspendingthe segment in the center-andandi segment in; substantially rigid relation to each other, 1t will be obvious that bytrigidly fasteningthe segment the telescope is also rigidly; fastened; It'is equally obvious that other ways of fastening might be used; a I mount .ointhe plate 2 a pairof brackets 18 and 19 respectively,together with a cap bracket.- 20, These brackets are disposed will a line parallelto therbar 7 and at oneside ofthe segn ent, An; elongated clampr ne n ber :21, square in cross-section, is mounted-to,

slide in-the bracket; 19 and is ,proyided with a cylindrical barrel 22-slidably engaging in a the \caip bracket 20 The barrel receives a COllQCl-SPlHII 8 wlnch-tends to force the an 1 rel ($1 0111; the cap ,-bnacket. The opposite end of the member is internally screw-threaded 1 to; receive a tangent; adjusting screw 24 which is rotatably confined in the bracket 18 By revolving the screw the clamp member is lo n gitudinall-y ad usted. Ontheiouter end of the screw a benelpmlon 25 1s mounted and;

meshes with: a similar-pinion 26 fixed on the, inner cnd; f a shaft 27 disposed at substan -i tiallyright angles to the screw. This shaft is-rmo ntedi 1 a b acke 8? at its inner end Y. These members support the usual telescope 11 which ismolmted adjusted by oscillating A spirit level 17 is mounted This rigid-clamping and association per,-

and also in a bracket 29 projecting from one of the standards. The outer end of the shaft pro ects beyond the Y margin of the plate 2 t andthasnitthumb Wheel 30 thereon.

inner end of the squared portion of the clampmember 21 is at the centralportion of the'plate 2 and carries a laterallypro jectililgiclampijaw rill into which the segment depends. A clamp screw-shaft 32 is thread ed through the member 21; at right: angles thereto and hasaclamp-head adapted-to bind on the segment imopposed relationito the topof the aw. By} tightening the screw-shaft so: that; its head -binds, the ,segment in the jaw ,-sa-id segment, is rigidly cured 1a gainst, further areuate movement, unit less the member 21 is adjusted. The screw-,

shaft includes Tnniyersal joint gt and is slidably mounted in; a :bnacket; 35. swiyeled onthe marginal portion of the plate 2,,Ar

thumb wheel 36 is mounted-on the outer. end of the screw-shafts The-segment hasonefa'ce provided with graduations ,1 which may be registered w ith graduationsontzthe{face of a yernieng'lin C ntact w hrth nneriperiph ry of e 6?; ment. The ,uerniert is lprouidedjwith concen-j tric lugs 38 .sli-dable .in sockets 3 9. r proj ec-ting from standards i0: mounted on the'plate An ad usting-screw All ismounted in the sai d: brackets and-base sleewe e2engaging itsi threaded portion, and: loosely connectedwith the uveri iers By revolving the .saidscrew thesleeve is moved longitudinally, and the Vernier given an adjustment,concentricto, 100 the segment. i

It will be readily, seen that by loosening theclamp screw-.shaftg82 the segment freedandmay, with the telescope and. supporting bar be. oscillated quickly. throughout 1 the full- ;amplitude .ofits ;p ossible movement; Likewise theltelescope may be rigidly fast: tened in any. adjusted position .by tightening, up said screw-shaft l/Vith; the segment, clamped in any position it might be necessary or desirable tofurthen adjust the -.tele-, scope and this may be readily; accomplished byi means of theutangential adjusting screw 24; which bodily moveslthe ;.member 21 carry-i ing the clamp 311and;head 33.,. Through the gr ad'u ations ofthe segment and the vyernier clt -eir. adjustments all, the functions. of the usual erticalarQ may behad-,which ,willj be apparent to those skill'ed'inthaart.

It. is j g in vpointed: out, that the telesc pe bei-ng rigidly mounted [on the supporting ban and, the a segment. beingrigidl-yf secured to the bar, the pants are rigidlyffastened in; V adjusted positionsby theclamping device;

uts th t g ntscrew 2eztoimparta minute t ad ustmenttothe parts without the presence o ltors onal strain Owing t ther t aldis:

a position of the segmentandclamping point and the balancing; of the ,parts ,..the latter, be:

ing due to relative location of the horizontal axls.

The foregoing description and illustration clearly express the invention, but it is to be understood that said illustration is merely an exemplification and the invention may be carried out in various other ways.

What I claim, is:

1. In a surveying instrument, the combination with a supporting base, an elongated supporting bar disposed above the base, and a telescope supported by the bar longitudinally thereof and above the latter, of a pair of supporting standards mounted on the base and pivotally supporting the bar and telescope from a point intermediate said bar and telescope, whereby said bar and telescope are substantially balanced.

2. In a surveying instrument, the combination with a supporting base, a supporting bar disposed above the base, and a telescope supported by the bar and above the latter, of a pair of supporting standards mounted on the base and pivotally supporting the bar and telescope from a point inter mediate said bar and telescope, whereby said bar and telescope are substantially balanced, and means for fastening the bar and tele-K scope in rigid relation to the supporting base in their adjusted positions.

3. In a surveying instrument, a support-v ing base, standards mounted on the base, a supporting bar disposed between the stand ards, and a telescope mounted on thebar longitudinally thereof and thereabove, in

combination with a shaft member pivotally supporting the bar and telescope for adjust ment in a vertical arc and engaging the standards so that the horizontal pivotal axis lies between the bar and telescope.

I. In a surveying instrument, a support ing base, standards mounted on the base, a supporting bar disposed between the standards, and a telescope mounted on the bar longitudinally thereof and thereabove, in combination with a shaft member pivotally supporting the bar and telescope for adjustment in a vertical arc and engaging the standards so that the horizontal pivotal axis lies between the bar and the telescope, and a fastening device for securing the bar and telescope in rigid relation to the supporting base.

5. In a surveying instrument, a supporting base, standards mounted on the base, a supporting bar disposed between the standards, and a telescope mounted on the bar longitudinally thereof and thereabove, in combination with a shaft member pivotally supporting the bar and telescope for adjustment in a vertical arc and engaging the standards so that the horizontal pivotal axis lies between the bar and the telescope, and

a fastening device for securing the bar and telescope in rigid relation to the supporting base, said device being capable of adjustment for adjusting the telescope in a vertical are after said device has secured said parts.

6. A surveying instrument including a supporting base, an elongated supporting bar pivotally supported on the base, a telescope mounted on the bar longitudinally thereof, a segment rigidly carried by the bar and depending therefrom over the base, and a fastening device carried by the base and engaging the segment.

7. Asurveyinginstrument including a supporting base, a supporting bar pivotally supported on the base, a telescope mounted on the bar, a segment rigidly carried by the bar and depending therefrom over the base, and a fastening and adjusting device carried by the base and including a clamp engaging the segment and a tangential screw member connected with the clamp.

8. In a surveying instrument, a supporting base, spaced standards mounted on the base, a supporting bar pivoted between the standards, a segment depending centrally from the bar and capable of oscillating the bar in a vertical plane, a telescope mounted on the bar, and an adjusting device engaging the segment for oscillating the telescope, bar and segment as a unit.

9. In a surveying instrument, the combination of a supporting plate, a pair of spaced standards mounted on the plate, a horizontal pivot shaft extending between and mounted in thestandards, a supporting bar rigidly mounted on the shaft at right angles thereto and depending from said shaft, supports at each end of the supporting bar, a telescope mounted in the end supports of said bar in rigid relation to said bar, a segment depending centrally and longitudinally from the bar and in rigid relation thereto, a fastening device mounted on the supporting plate and arranged to clamp and release the segment, and means for adjusting the device to impart an arcuate movement to the segment to oscillate the telescope in a vertical plane.

10. In a surveying instrument, the combi- FRANKLIN S. CLARK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Eatents, Washington, D. G. 

